A former energy company executive testified yesterday that his employees worked on an expansive reconstruction of the house of Sen. Ted Stevens (R), who is under investigation in a federal probe of corruption among Alaska lawmakers.

Bill Allen, the former chief executive of Veco Corp., said he personally oversaw the rebuilding of Stevens's house near Anchorage, visiting the home about once a month, and gave the senator furniture. "I gave Ted some old furniture," Allen testified. "I don't think there was a lot of material. There was some labor."

Contractors previously told a federal grand jury that Veco executives supervised renovations at Stevens's house and that bills for the work went to Veco for Allen's approval. But yesterday was the first time that Allen, who has pleaded guilty to bribing state lawmakers in Anchorage, named Stevens publicly.

Allen testified in federal court in Alaska in the trial of a former state legislator whose case is part of a larger corruption investigation that has ensnared Stevens's son, Ben Stevens, a former state senator. Allen said yesterday that Ben Stevens accepted $4,000 a month in bribes, disguised as consulting fees, while he was in the state legislature.

Ted Stevens has told Alaska reporters that he paid every bill he received for the renovation. In a letter to a friend who is a former federal prosecutor, Stevens said he paid more than $130,000 for the renovations, according to the Seattle Times, which reported on the document.

Yesterday, Stevens said in a statement that he does not want to make any comment that might influence the investigation. "I urge Alaskans not to form conclusions based upon incomplete and sometimes incorrect reports in the media. The legal process should be allowed to proceed so that all the facts can be established and the truth determined," he said.

Federal investigators have been examining federal contracts awarded to Veco, particularly those from the National Science Foundation in 1999 and 2004. The 1999 contract was worth $45.4 million, while the second is worth as much as $93 million through 2011, NSF officials told The Washington Post last month. They said Veco won the contracts, after competitive bids, to help the agency with research operations in the Arctic Circle.

In July, FBI and Internal Revenue Service agents raided Stevens's house in Girdwood. They spent more than 10 hours there, taking photographs and hauling away unspecified items.

Stevens, 83, is the longest-serving Republican senator. He joined the Senate in 1968 and has become one of the most powerful members of Congress. For six years, he chaired the Appropriations Committee, steering hundreds of millions of dollars to his state. He now serves as the top Republican on the Commerce, Science and Transportation Committee, which has oversight over several industries critical to his state, such as fisheries.

He has said he plans to run for reelection next year. Democrats, who plan to make the corruption investigation a major issue in the campaign, regard Stevens as vulnerable.

Stevens is among more than a dozen current and former members of Congress who have come under federal investigation in the past three years because of their ties to lobbyists and corporate interests. Yesterday, President Bush signed into law legislation that will require lawmakers to disclose more of their efforts to fund pet projects and raise money from lobbyists.

Allen pleaded guilty in May to paying more than $400,000 in bribes to five members of the state House and state Senate in Alaska, as well as "other public officials."

His testimony yesterday about Stevens came during the trial of former state House speaker Pete Kott, who is accused of supporting favorable tax legislation sought by Allen in exchange for cash and the promise of a future job.

Prosecutors have introduced a series of secretly recorded phone conversations of Allen and Kott, as well as recordings from a hotel suite one block from the state Capitol in Juneau that Allen regularly used for lobbying lawmakers.

In court, Allen acknowledged for the first time that in 2000 he oversaw the rebuilding of Stevens's house, which involved lifting the existing A-frame structure up on stilts and building a new floor underneath, more than doubling the size and value of the structure.